Auxiliary contact device for electric contactors



Jan. 22, 1952 o. ELLIS 2,583,139

AUXILIARY CONTACT DEVICE FOR ELECTRIC CONTACTORS Filed Nov. 1, 1949 2 SHEETS-SHEET l III Fig.7.

37 38 27 36 3s v A 29 32 I "Zd WITNESSES: a v INVENTOR 24 542/] DelbertEllls.

ATTORNEY Jan. 22, 1952 D. ELLIS 2,583,139

- AUXILIARY CONTACT DEVICE FOR ELECTRIC CONTACTORS Filed Nov. 1, 1949 2 SHEETS-SHEET 2 Q 25 2 e -29 36 -26 38 -21 3 I5 37 I L 0 Fig.4.

l g Q ,24 4 n INVENTOR DelbertEl'lis.

ATTORNEY Patented Jan. 22, 1952 AUXILIARY CONTACT DEVICE FOR ELECTRIC CONTACTORS Delbert Ellis, Beaver; Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 1, 1949, Serial No. 124,921

My invention relates to auxiliary contact devices for electric contactors and involves improvements over the contact devices disclosed in the copending patentapplication Serial No. 54,098 of R. Immel, for Contact Assemblies, filed October 12, 1948 now Patent No. 2,546,001,. March- 20, 1951, and assigned to the assignee of the present invention. 7

It, is an object of my invention to provide auxiliary contact devices, applicable as an interlock contact or the like accessory. or part of a contactor, that lend themselves readily to being used in various numbers and in various combinations of make or break contacts. I v

Another subsidiary object of my invention is to devise an auxiliary or mterlockcontact device for contactors thatcan be adapted either for use as a make contact or as a break contact by a simple change in arrangement that does not affect the positioning or mounting of the appertaining insulatin base so that the latter may form an integral part of the contact-carrying insulating body of the contactor, thus reducing the space requirements of the auxiliary contact assembly without foregoing its advantage of adaptability to make or break operation.

Also, an object of my invention is the provision of auxiliary contact devices that permit being attached to a contactor and to one another in a continuous series of any desired number of units.

A further object is to design the auxiliary con tact devices in such a manner that a single pair of screws not only holds all its individual and diiferently. arrangeable parts together but also attaches the device as a unit to the contactor,

as well as to an adjacent similarunit sothat, regardless of the number of mutually attached devices,.only one pair of screws is needed for each of them to perform all fastening functions. 7

Still another object of my invention, in conjunction with any of the foregoing objects, is to permit making the individual metal members of the auxiliary contact device of punched sheet metal parts of simple and straight sha'pe thu's reducing the manufacturin cost of such devices.-

These and other objects, as well as the means according to the invention for achieving them, will be apparent from the following description of the embodiments of the invention exemplified by the drawings, in which: 7

Figure 1 shows a front view of an electromagnetic contactor equipped with three auxiliary contact devices according to the invention; Fig.2 shows a modified part. sectional side view of the same contactor, the section being 8 Claims. (01. 200-166) taken in the plane denoted in Fig. 1 by the line II-II which is through one auxiliary contact device and shows that device as it appears without the adjacent auxiliary switch of Fig. 1

- mounted thereto;

Fig. 3 shows a section through one of the auxiliary contact devices of the contactor, the section being taken along the plane indicated in Fig. l by the line IIIIII;

Fig. 4 is a view of the same contact device seen from below Fig. 3;

Fig. 5 is a corresponding top view;

Fig. 6 is a section through two of the contact devices of the contactor, the section being taken along the plane denoted in Fig. 1 by line. VI-VI, and

Fig. 7 is a cross-section comparable with Fig. 3 but showing .the device set for operation as a break contact. e

As apparent from Figs. 1 and 2, the illustrated contactor has a sheet metal base plate I with which it is to be mounted on a panel or other support. An insulating base 2 is firmly attached to the upper portion of a base plate I and carries the stationary main contacts of the contactor. The insulatin body 2 also accommodates the auxiliary or interlock contact devices according to the invention proper and may either from part of such an auxiliary contact device or merely serve as a support for such a device as will be explained in a later place. An arc box structure 3 is mounted on the insulating body 2. The structure 3 encloses the stationary main contacts as well as the movable contacts to be actuated by the electromagnet of thecontactor. The movable contacts (not shown) are attached to arms '4 of an insulating structure 5 which forms part of the movable armature assembly. The insulating structure 5 is firmly secured to a sheet metal cradle 6 which is pivoted for angular movement. The pivot bearing is not shown in the drawings, but the location of the pivot axis is indicated in Fig. 2 by the center of a circle denoted by]. The pivot bearing is adjacent to a bracket 8 which is firmly secured to the base plate I. Also attached to the base plate is a second bracket 9 which, together with bracket 8, serves for mounting the electromagnet of the contactor by means of a front plate Ill. The frame structure I l of the electromagnet is firmly attached to the front plate Ill and carries the. appertaining energizing coil 12. The magnetic armature I3 is pivoted for limited angular movement about a pin M with which the armature I3 is attached to the above-mentioned cradle 6.

124,922, filed on the same day as this application,

now Patent No. 2,550,110, April 24, 1951, entitled Magnet Assembly for Contactors and assigned to the assignee of the present invention.

The illustrated contactor is equipped with three auxiliary contact devices, each of which embodies features of the present invention. These three interlock contacts are denoted as a whole by IT, I8 and IQ, respectively. As apparent from Fig. 1, one contact device I9 is disposed at one side of the contactor to be actuated by the lateral arm It of the armature assembly, while two auxiliary contact devices I! and I8 are attached adjacent to each other at the other side of the contactor to be actuated by the lateral arm |5. With the exception of the insulating base, the individual parts of the three auxiliary contact units are similar and mutually exchangeable. For that reason, corresponding parts of the different devices are denoted by the same respective reference numerals with the exception of the bases.

The base member of the auxiliary contact unit H, which is illustrated in cross section in Fig. 2 forms an integral part of the above-mentioned insulating body 2 of the contactor. This applies also to the contactor device l9. In contrast thereto, the device If! is designed as a unit completely separate from the contactor and there fore given its own base 20. However, the features mentioned presently are common to all three illustrated auxiliary contact devices.

As shown in Figs. 2 and 3, the insulating base 2 or 29 of the auxiliary contact device has two recesses 2| and 22 at its bottom surface for the reception of nuts appertaining to two respective fastening screws 23 and 24. These screws secure an insulating top portion 25 to the base. In the case of the switch ll having the base 2, if an auxiliary contact unit such as |8 is not secured thereto, the screws 23 and 2 are secured by nuts mounted in recesses 2| and 22 as seen in Fig. 2. However, if a switch such as |8 is utilized screws 23 and; 24 of Fig. 2 thread into lugs 45 having threaded holes 42 therein. This secures the base 26 of switch unit It to main base 2- as will be explained hereinafter. The base 2 or 20 is further provided with a central opening 26 of rectangular cross section. The lower portion 21 of a fiat plunger 28 passes through the opening 26 and is displaceable therein in the illustrated assembled condition of each unit. At the front surface of the insulating base, the opening 26 for plunger 28 is surrounded by a relatively shallow recess 29. The front face of the base has two grooves which extend from the out side to the recess 29 and accommodate two respective contact strips SI and 32 (Figs. 2 to 5) so that these contact strips are securely held in position by the top member 25 and the fastening screws 23 and 24 when the unit is in assembled condition. The fastening screws 23 and 24 traverse correspondin openings in the contact strips 3| and 32.

The contact strips 3| and 32 preferably consist of solid silver so that, after considerable wear, they may be turned in the same location to provide a new contact surface. However, contact strips of different design are also applicable, such as copper strips with contact buttons or areas of silver.

The top member 25 has a relatively deep recess 34 at its rear surface. The flat plunger 23 has a laterally projecting abutment 35. A helical compression spring 36 bears at one end against the abutment 35 while the other end engages the deepened central portion of the recess in the insulating base member. Loosely seated on the plunger 28 is a contact member 37 with two contact buttons for engaging the stationary contact strips 3| and 32. Another helical spring 38 has one end stuck through a hole in plunger 28 while the other end biases the contact member 31 against the abutment 35.

The two contact devices I! and I8, assembled as shown in Figs. 2 and 3 and described in the foregoing, operate as make contacts. The con tact member 31 and the plunger 28 are normally biased by a spring 36 to the illustrated positions in which the circuit between the stationary contact strips 3| and 32 is open. When the contactor is energized so that the armature assembly moves clockwise about the pivot axis I (Fig. 2), the arm l5, near the end of its travel, engages the plunger 28 of the auxiliary contact devices I! and I8 and moves them toward the right (Figs. 2, 3), thus closing the interlock or auxiliary contact device in the desired time relation to the closing of the v contactor main contacts. When the coil of the contactor is deenergized, the armature returns to the illustrated position due to the bias of a kickout spring (not illustrated) so that the auxiliary contact devices return to the illustrated open positions.

It is an essential advantage of the present invention that the above described contact devices can readily be modified to serve as break contactswithout requiring parts other than those needed for the make contact. An assemblage of the same parts as above described, but operating as a break contact, is illustrated in Fig. '7.

The only difference between the assemblage according to Fig. 7 from that described in the foregoing lies in the fact that the contact member 37 is reversed so that it contactsthe other side of the plunger abutment 35, and that the stationary contact strips 3| and 32 are inserted through lateral openings 4| and 42 (see Fig. 3)" ofthe" top member 25 instead of through the above-mentioned grooves in the front surface of the base member 2 or 20. Consequently, all illustrated auxiliary devices, according to the l. vention, lend themselves readily for use as make contacts or break contacts dependent upon the requirements of each particular application. As a result, the number of different parts needed for each installation or to be kept in store by the contractor or manufacturer is considerably re duced. In both modes of assemblage the screws 23 and 24 serve to hold the top member 25 on the base and also to secure the stationary contacts of the device in proper position. The design and the position of the insulating base member relative to the contactor is the same regardless of whether the device is used as a make contact or break contact. This has the considerable advantage exemplified by the illustrated contactor, that when the base of the auxiliary contact device is to form an integral part of the base of the contactoi', one and the same contac'tor base is applicable for auxiliary contacts or interlocks oi make or break operatlen. This has also the advantage that the space required for the auxiliary device is considerably reduced espectially in comparison with devices that require a reversed mounting of the appertaining insulating base relative to an insulating subbase of the contactor.

Referring to Fig. 1, it will be remembered that the top member of the contact device I! is mounted directly on a properly designed portion of the insulating body 2 which forms an integral part of the electromagnetic contactor, while the adjacent device I8 is equipped with its own insulating base member 20. As apparent from Figs. 4, 5, and 6,- the insulating base member 20 has two lateral projections and 46 which match the recesses 2| and 22, respectively, of the adjacent base 2. threaded bore 41 or 48. The base 20 of unit l8, after having its projections 45, 46 inserted into the recesses 2|, 22 of the base 2, is fastened in position by means of the screws 23 and 24 of the unit I! which are screwed into the bores 41 and 48 respectively. Consequently, the same two screws of unit I! that serve to hold all parts of this unit together have the additional function of also securing the entire unit [8 to the unit ll. If desired, one or more additional units according to the invention can be added to unit [8. In

that case, the two screws 23 and 24 of unit l3 serve to secure the additional unit in position. In this manner the present invention permits more readily than heretofore possible an adaptation to a large 'variey of requirements, indeedto practically all occurring combinations of auxiliary make and break contacts. A groove 49 may be molded into the base 20 in order to increase the creep resistance between the terminals of adjacent auxiliary contact devices.

It will be obvious to those skilled in the art after a study of this disclosure that devices according to the invention can be modified in various respects as regards design details and shapes without departing from the foregoing objects and advantages of the invention and without departure from the essential features set forth in the claims annexed hereto.

I claim as my invention:

1. An auxiliary contact device for electric contactors, comprising an insulating base member, an insulating top member disposed on said base member and forming together therewith a cavity, a plunger displaceably engageable with said two members and extending through said cavity, a movable contact member reversibly mounted on said plunger in said cavity and having two selective positions on said plunger for make and break operations respectively, biasing spring means disposed on said plunger in said cavity, two stationary contact members to be electrically interconnected by said movable contact member, said base member and said top member forming between each other two seats on opposed sides respectively of said cavity to accommodate said respective stationary members for one of said operations, said top member having two openings at opposite sides respectively of said cavity for accommodating said respective stationary members for the other operation, two spaced fastening screws traversing said top member and base member at said respective seats, and said two stationary contact members having respective holes engageable by said respective screws when said stationary members are located at said seats Each projection 45, 46 has a 1 said top'meihber having respective recessed abutment faces for said respective screw heads, said. respective openings of said top member being flush with said faces so that said faces form supports for said respective stationary contact members when said latter members are placed through said openings.

3. An auxiliary contact device for electric contactors. comprising an insulating base member, an insulating top member disposed on said base member and having a cavity facing said base member, tw head screws traversing said top member and said base member on both sides respectively of said cavity for fastening said top member on said base member, a plunger displaceably engageable with said two members and extending through said cavity, a movable contact member reversibly mounted'on said plunger in said cavity and having two selective positions on said plunger for make and break operations re-- spectively, biasing spring means disposed on said plunger in said cavity, two stationary contact members to be electrically interconnected by said movable contact member, said base member having two mutually aligned grooves facing said top member andextending into said cavity at both sidesrespectively of said cavity to accommodate said respective stationary contact members for make operation, said top member having two I mutually aligned holes at'both' sides respectively of said cavity and having two mutually aligned abutment laces flush withsaidfrespective holes for accommodating saidrespective stationary members for break operatiomsaid screws being located at said'respective'faces andsaid station ary contact members having respective holes en gageable by said respective screws.

4. An auxiliary contact device for electric contactors, comprising an insulating base member, an insulating top member disposed on said base member and forming together therewith a cavity, a plunger displaceably engageable with said two members and extending through said cavity, a movable contact reversibly mounted on said plunger in said cavity and having two selective positions on said plunger for make and break operations respectively, two helical compression springs surrounding said plunger within said cavity at both sides respectively of said movable contact, two stationary contact strips to be electrically interconnected by said movable contact, said members having at either side of said cavity two seats for selectively accommodating one of said respective stationary contact members for said make and break operations respectively, and two screws traversing said two insulating members and said respective stationary contacts and said seats at said respective cavity sides and forming the exclusive fastening means for holding all said parts together.

5. An auxiliary contact device for electric contactors, comprising an insulating base member, an insulating top member disposed on said base member and forming together a cavity, a plunger displaceably engageable with said two members and extending through said cavity, a movable contact removably seated on said plunger within said cavity, two stationary contact strips loosely inserted through one of said insulating members and extending from without said insulating member to within said cavity and being auaawa biasing spring and a helical contact-pressure spring loosely seated on said plunger within said cavity at both' sidesrespectively of said movable contact, and two screws, each traversing said two members and onset said respective stationary contact strips so as to hold all said parts toether. v

6. An auxiliary contact device for electric contactors, comprising an insulating base member, an insulating top member disposed on said base member and forming together a cavity, a plunger displaceably engageable with said two members and extending through said cavity, movable contact means and biasing spring means disposed in said cavity and ,operatively connected with said plunger, two stationary contact strips loosely inserted through one of said insulating members and extending from without said one insulating member to a position therewithin in the path of movement of the movable contact means said base member having two recesses located at its bottom and open toward one side of said base member, said base member having two lugs at its opposite side, said lugs having a shape inversely corresponding to said respective recesses, two fastening screws extending through both insulating members and said contact strips into said respective recesses, and said lugs having respective bores at locations corresponding to that of said screws relative to said respective recesses, whereby the device can be assembled with a similar one 'by placing the lugs of one device into the recesses of the other.

7. An auxiliary contact device for electric contactors, comprising an insulating base member of elongated and substantially rectangular shape, an insulating top member disposed on said base member, movable contact means disposed between the insulating top and bottom members and having an actuating plunger extending through said top member, a pair of stationary contact strips engaged with at least one of the insulating mem bers and having portions thereon contacted by said movable contact means, said base member having two recesses spaced from each other and open toward the bottom. surface and one of the longitudinal sides of said base member, said two members having matching holes extending into said respective recesses, said stationary contact strips each having a hole therein aligned with one of the matching holes, two fastening screws extending respectively through said matching holes and the hole in the associated stationary contact strip into said respective recesses, said base member having two mutually spaced lugs at its other longitudinal side and adjacent to said respective recesses, said lugs having a shape in versely corresponding to said respective recesses and having respective bores at locations corre-- sponding to that of said screws relative to said respective recesses, whereby the device can be assembled with a similar one by placing the lugs of one device into the recesses of the other and said screws secure the insulating members, the stationary contact strips and the lugs together.

8. In an auxiliary contact device according to claim 7, said insulating top member having a smaller width than said base member so that a base member is uncovered alongside said top member, and a groove extending along said portion for increased creep distance.

' DELBERT ELLIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

